The Startup plan allows you to use Rails LTS for up to two applications.
Coherent services that are comprised of multiple Rails applications count as a single application for the purpose of Rails LTS licensing. For example, if distinct Rails applications are used for the frontend and backend of the same site, this counts as a single application. Also if you operate multiple staging and production instances for the same site, this counts as a single application.
Applications that are used to service distinct sites or clients are counted as separate applications.